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ISAC-SX
PEB 3086
Description of Functional Blocks
Data Sheet
30
2003-01-30
3
Description of Functional Blocks
3.1
General Functions and Device Architecture
Figure 4
shows the architecture of the ISAC-SX containing the following functions:
S/T-interface transceiver supporting the modes TE, LT-T, LT-S, NT and Intelligent NT
Different host interface modes:
- Parallel microcontroller interface
(Siemens/Intel multiplexed, Siemens/Intel non multiplexed, Motorola modes)
- Serial Control Interface (SCI)
Optional indirect register address mode reduces number of registers to be accessed
to two locations
One D-channel HDLC-controller with 64 byte FlFOs per direction with programmable
FIFO block size (threshold) of 4, 8, 16 or 32 byte for receive direction and 16 or 32
byte for transmit direction
Support of firmware download via one B-channel HDLC-controller and FlFOs with
reduced functionality
IOM-2 interface for terminal (TE mode), linecard (LT-T or LT-S) or NT applications
IOM handler with controller data access registers (CDA) allows flexible access to IOM
timeslots for reading/writing, looping and shifting data
Synchronous transfer interrupts (STI) allow controlled access to IOM timeslots
Flexible timeslot assignment of HDLC controllers on IOM for IDSL support
MONITOR channel handler on IOM-2 for master mode, slave mode or data exchange
C/I-channel handler and TIC bus access controller
D-channel access mechanism in all modes
D-channel priority handler on IOM-2 for intelligent NT applications
Capability to control the start of the multiframe for synchronization from external
signals (M-bit input pin in LT-S/NT mode, M-bit output pin in TE, LT-T mode)
Auxiliary interface with interrupt and general purpose I/O lines and 2 LED drivers
LED connected to pin ACL indicates S-interface activation status automatically or can
be controlled by the host
Level detect circuit on the S interface reduces power consumption in power down
mode
Two timers for periodic or single interrupts (periods between 1 ms and 14.336 s)
Clock and timing generation
Digital PLL to synchronize the transceiver to the S/T interface
Buffered 7.68 MHz oscillator clock output allows connection of further devices and
saves another crystal on the system board
Reset generation (watchdog timer)